APP packet name length about uvgrtp

[jrsnen]

Hello,

there is a problem with the names of the APP packets. API guide states the following:

When in fact, any name that is longer than 3 characters results in name corruption. For example, a packet named "123" produces:

whereas packet named "1234" produces:

In the rtcp_app_packet declaration the name is represented as

So it is converted to an array with a length of [4] and is probably null-terminated, because the function takes char pointer

I'm actually not convinced there is a problem. When looking at the spec (RFC 3550), 4 is the correct length for the name

Then, when looking at the name

I get the impression that you are supposed to use all 4 bytes for your name and not less. How uvgRTP handles this is just assume there are 4 characters there and copies them (this could probably be handled better, but it works in context of the specification.) This means that 123 will have the null-termination even though it is not supposed to have it. In case of 1234, it is copied without the null-termination, but this is actually correct, since the termination is not supposed to be there. In other words, when printing the name, you should not assume it is null-terminated, because it is not supposed to be.

 rtp_error_t send_app_packet(char *name, uint8_t subtype, size_t payload_len, uint8_t *payload);

You are right, that the char* in the API is misleading.

So I guess this is the intended behaviour with a misleading API guide. But I think that 3 characters long names are a bit short.
Either the API should be fixed, or the names allowed to be longer, API fix is easier tho :)

The length is specified by the RFC, so it cannot be increased. The API should probably be improved in some way.

p.s also when converting the name from the app packet that we receive back to char*, it becomes non null-terminated.

I'm not super familiar with C, but maybe you should use a conversion function that adds the null-termination.